DE1643964A1 - Process for the selective extraction of complex-forming ligands, preferably butadiene and other mono- and diolefins - Google Patents

Description

Process for the selective extraction of complex-forming Li ^ anden _y, preferably butadiene and other iono- and diolefins.

The present invention relates to a method for the selective recovery of complex-forming ligands which preferably with solid copper (I) chloride, copper (I) bromide or copper (I) iodide as absorbent resistant Form complexes, taking a charge Ligands that boil in the same range, are difficult to remove, contains impurities that form complex complexes, with the solid Gu (I) halide absorbent in contact brings to effect the complex formation (either in the gas phase or in the liquid phase) or the ligand with the absorbent in the presence of an agent brings into contact, which is able to remove the desired, complex-forming impurities substantially, which (once complexed with the absorbent) are extremely difficult

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the product obtained (and otherwise heavily purified) Ligands obtained after desorption (complex breakdown) of the solid absorbent are to be removed, such as a purity improving agent consisting of the solid Cu (I) halide absorbent and that therewith highly associated contaminant removing agents (described below) with or without an inert dispersion-forming diluent is available. The contaminant removing agent is an agent which (a) is substantially inert, i.e., in the preferential complexing of the ligand to be recovered has no adverse effect, (b) the complex-forming capacity or activity of the absorbent in the concentrations at which the mixture removes the impurities very effectively removes, does not destroy or inhibits, (c) in the reaction by which the ligand is obtained, is inert so that its chemical identity remains unchanged and (d) easily, e.g. by simple evaporation or other simple distillation processes is separable from the purified ligand obtained as product. That removes the impurities Agent consists of (A) compounds of the formula

C-N

in which R "is an alkyl group having 1 to 12 carbon atoms and η is an integer from 2 to 12, or (B) compounds of the formula

0 ^ R ' R * C - N

R "

in which R and R ^{1 are} hydrogen or alkyl groups with 1

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are up to 18 carbon atoms and R "is an alkyl group with 1 to IB carbon atoms, or (C) mixtures of compounds (A) and (B).

According to a preferred embodiment of the present invention, the compound (B) is an N, N-dialkylaiiiid. -τ alkanecarboxylic acid with 1-4 hydrocarbon atoms in the "M-alkyl groups and 1 to 18 carbon atoms in the oäurerest and the compound (A) is an N-alkylpyrrolidone with 1-4 carbon atoms in the 21-alkyl radical.

In the case of those with Cu (l) -halo ^ enide absorbents, such as Cu (I) chloride, working processes for the recovery of koa: plex-forming ligands from feeds in which the latter are included, it is extraordinary ■ Difficult, obstructive, highly complex-forming impurities to be removed from the charge, especially if the permissible concentration of a such contamination in the ligand obtained as a product because of the high degree of purity required is low. For example, in order to be able to use the 1,3-butadiene obtained effectively for carefully controlled polymerization reactions, it should be less than about 200 parts / million vinyl acetylene, and preferably, less than about 100 parts / million vinyl acetylene. Some uses for 1,3-butadiene are even only less than 5C parts / i-iillion vinyl acetylene permitted. Although x \ ethylacetylene and ethylacetylene in the Polymerization of highly pure 1,3-butadiene inhibited however, vinylacetylene is the one who should most annoying pollution, as it is already relatively moderate small concentrations, e.g. 300 parts / million can lead to premature polymerisation of the butadiene, leads to a low yield of polymers with the desired molecular weight and furthermore the desired polymerization reactions of 1,3-butadiene destroyed. Although ethyl and ethyl acetylenes using Cu (I) -

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chloride absorbents proceeding essentially in the liquid dispersed phase Complex formation process and dispersion desorption process can be eliminated, such a method for removing the troublesome vinyl acetylenes is not always sufficiently selective that the purified 1,3-butadiene obtained can be used directly for the polymerization would allow. This is particularly the case where 1,3-butadiene from uses with high concentrations is obtained on vinyl acetylene. There are therefore often pretreatments of use and / or post-treatments of the product, such as hydrogenation of the feedstock or the butadiene obtained as product, to convert the vinyl acetylene to other materials such as 1,3-butadiene or ethyl acetylene, the latter does not have nearly as strong a complexing effect with the Ou- (I) chloride serving as absorbent as the ligand to be recovered, e.g. 1,3-butadiene. aside from that the use of such pre- or post-treatment processes increases the overall costs and reduces the considerable ones Advantages offered by absorbent production methods for ligand production.

Other troublesome impurities which the recovery of the complex with Cu (I) halide Making ligands difficult are listed below:

Ligand obtained as a product. Impurity

Ethylene acetylene and carbon monoxide

All methyl acetylene

Propylene methylacetylene

Acrylonitrile acetonitrile

Isoprene vinyl acetylene and ethyl

acetylene

While most of these impurities are not as difficult as vinyl acetylene is obtained from yours

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To remove 1,3-butadiene, nevertheless it is desirable to improve the removal of such compounds from the respective ligands obtained as a product, if they ar beutenden with Gu- (I) -halide absorption means Procedures were obtained. The main aim of the present invention is therefore to improve the Purity of the ligand obtained by excretion or removal of otherwise difficult to remove, strongly complex-forming impurities with closely adjacent boiling points from the ligand obtained as a product, which is in the gas phase or methods performed in the liquid phase using the Ou- (I) halide absorbents selected above was obtained.

A feature of the present invention is that in the selectivity for the Ge of the desired complex-forming ligands winnung significant improvements are possible if, when having AbSOi ¹ Ptionsmitteln working method for recovering ligands the above Cu (I) -halogenidabsorptionsmittel be used while maintaining the high absorption capacity of the absorbent. Further advantages according to the invention are that the rate of complex formation, ie the rate at which the ligand obtained as the product is selectively removed from the insert, and also the activity of the Ou- (I) halide absorption particles, namely the ability of these absorption particles to form complexing ligands over longer periods of time Repeatedly removing periods of time away, not being degraded. According to the invention, the disadvantages previously occurring in the processes using Cu (I) halide absorbents are eliminated, but the complex-forming ability of the absorbent, its activity or the rate of complex formation are not reduced.

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While the reasons for the advantages achieved by the present invention are not fully understood, it is believed that when the contaminant removing agent is used, the Cu-II ions on the Cu-I halide absorbent particles are blocked during complex formation will. When using the absorbent, it was found that a certain part of the Cu-I halide is oxidized to divalent copper (Gu-II-) and these Gu-II sites on the absorbent presumably complex formation with the highly complex-forming contaminated present in use Increase material. For example, it has been found that the presence of varying amounts, e.g., 2 to 10 wt Absorbent working process for the recovery of I ₁ 3-butadiene with the 1,3-butadiene forms a mixed complex. The complex-bound vinyl acetylene is therefore present in the 1,3-butadiene obtained after koiaplex degradation (desorption) of the absorbent. However, the present invention is not limited to any theory since, for a successful process sequence, the use of the selected impurity removing agent during complex formation easily achieves the above-mentioned beneficial results.

A salient observation regarding the close affinity of the impurities removal Means (A) and (B) to the solid Gu-I halide absorbent is the fact that the contaminant removing agent is tight during the process appears to be associated with the solid absorbent, glad of the absorbent that is present during the Complex formation, stripping and complex degradation were taken, show a fairly constant concentration

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tion of the agent removing the contamination »thereby the selective complex formation in such places of the absorbent, perhaps places of the Cu-II -ions, indicated, which would otherwise preferably complex with vinyl acetylene.

Suitable, non-limiting examples of impurities removing agents of the formula (A) are: N-ethylpyrrolidone, N-ethylpyrrolidone, N-propylpyrrolidone, N-butylpyrrolidone, N-amylpyrrolidone, N-hexylpyrrolidone, N-decylpyrrolidyl, -Dodecylpyrrolidone, Ni ^ ethyl-ß-propiolactam, N-ethyl-ß-propiolactaia, N-decyl-ß-propiolactam, wiuethyl-f-caprolactam, N-ethyl-HL-caprolactam, N-decyl- ^ -caprolactani, N -kethyl- Ciy-decanolactam, N-diethyl- (JJ- dodecanolactam and G-mixtures of two or more of the above compounds.

Suitable, non-limiting examples of impurities removing agents of the formula (B) are: "£> iethylformamide, N-ethylformamide, N-propylformamide, N-butylformamide, N-amylformamide, N-hexylformamide, N-decylformamide, N-dodecylformamide, N , N-dimethylformamide, N, N-diethylformamide, Ν, Ν-di-n-propylformamide, N, N-di-n-butylformamide, Ν, Ν-diamylformamide, Ν, Ν-dihexylformamide, Ν, Ν-didecylformamide, Ν, Ν -Didodecylformamide, N-methyl-N-ethylformamide, N-i'iethyl-N-propylformamide, N-mono- and Ν, Ν-dialkyl caproamides with 1-18 carbon atoms in the alkyl groups, for example N-kethylcaproamide, N, N-dimethyl caproaaiid, N-dodecylcaproamide, NjN-didodecylcaproamide, N, N-dimethylcaprylamide, Ν, Ν-dimethyllauramide, N ₁ N-dimethylpalmitamide, NN-dimethyloleylamide, Ν, Ν- ^ imethylheptadecylamide, NjN-dimethylheptadecylamide, and NjN-dimethyloctadecylamide and the mixture of two or more of the above listed compounds.

According to the invention, mixtures containing one or more of the compounds listed above,

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belonging to the group of formula (A) and / or (B), can be used. One to remove vinyl acetylene mixture of materials of the formula that is particularly suitable in the process for the production of 1,3-butadiene (B) is a mixture of Ν, Ν-dimethylcaprylamide and N, N-dimethyl caproamide.

The concentration of the above, according to the inventive improved method for Ent f eration of impurities to be used materials can be between 0.001 and 10 wt .- ^, based on the Amount of Cu-I halide absorbent present, lie. From the point of view of the composition relates the present invention therefore relates to the use of purity-improving dispersion mixtures which consist of

an inert liquid diluent and as a waste

/firm,

sorbents used'Cu-I (Gl, Br or I) consist, that is, from 0.001 to 10.0% by weight of an impurity removing mixture (A) and / or (B) to the amount of the fixed in the disp'ersion Ou-I halide absorbent, in a compound contains. Of course, the purity-improving mixtures in processes for the production of ligands contain which are carried out in the gas phase, such a liquid diluent, but consist from the solid'Cu-I-halOfeenidabsorbent and the closely related contaminant removing agents (A) and / or (B). In the latter case (gas phase) the purity enhancing blends consist essentially of 90 to 99.999 wt% solid Cu-I halide absorbent and 0.001 to 10.0 wt. # of the closely related contaminant removing agent. Usually, however, the concentration of the contaminant removing agent is from about 0.01 to 3 wt .- #, based on the amount of Cu-I halide present. Preferably, sufficient amounts of the contaminant removing agent are used, to ensure sufficient removal of the highly mixed complex

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to secure forming contaminating material. When using dispersion processes

then, in order to avoid localized copper deposits on conventional steel reactors, the solubility limits of the dispersing diluent for a given, specific, impurity-removing agent should be observed in order to avoid localized electrolytic reduction of the Cu-I halide to metallic copper, which is caused by the localized build-up is caused by insoluble, excess amounts of the polar amide material. "Excess amounts ^w are understood to mean those amounts which are not firmly and closely bound to the solid Ou-I halide absorbent. The preferred concentration of the contaminant removing agent (A) and / or (B) is for most cases about 0.1 to 2 wt .- $, based on the amount of Gu-I-halo & enide present.

The copper deposition as a result of the localized Occurrence of excessive amounts of the contaminant removing agent (A) and / or (B), the is insoluble in the dispersing diluent, should not have a strong Ou-I halide absorbent know ratio be confused with Cu-II chloride and metallic copper, which is replaced by basic Nitrogen compounds, e.g. organic amines, are favored. Organic amines should therefore be based on their pronounced tendency to favor a severe disproportion of the as an absorbent used Cu-I-haiogenids and related ones Ineffectiveness as a means of removing contaminants Not used.

has already been mentioned, the complex formation can either be in the gas phase or in the liquid Phase proceed. If the complex formation in the

BATH 109839/1624 **

Gas phase takes place, the particles of the particular Cu (I) halide used as an absorbent as a rigid layer or as a fluidized bed (in which part of the purified, recovered ligand and nitrogen or another inert gas can be used as the fluidizing gas) or they can be in a feed line or a similar equivalent type of vortex vessel. The one containing the ligand to be obtained Use current is then used with the particles of the as Absorbent serving Cu (I) halide in Be touch brought. This contact is made in the gas phase to achieve complex formation. The for the complex formation in the gas phase depends largely on the temperature and pressure conditions used Composition of the feed stream containing the ligand and the specific ligand to be obtained therefrom away. If, for example, the ligand to be obtained is 1,3-butadiene and the feed stream is largely exhausted a mixture of 1,3-butadiene and butenes (butene-1 and isobutylene), then complex formation can occur can be effected rapidly at 2 to 49 C and corresponding pressures of 1 to 7.3 kg / cm. The complex formation is carried out for a sufficient period of time so that essentially all of the electricity in use ligand containing complex bound v? ird. Of the Contaminant removing agent is usually applied to the particles of the absorbent Gu (I) halide by a conventional coating method upset. The material can be applied to the particles of the absorbent, for example Spraying, dipping, or soaking the parts in a solution of the contaminant-removing mixture etc. (any method can be used that allows adequate deposition a sufficient amount of the contaminant removing Material is secured that effectively eliminates the contaminating kafcerial associated with the im

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Ligands containing feed stream strongly leads to the formation of an i'iischkomplexes). Care should also be taken to maintain the above-described sufficient concentration of the contaminant removing agent during complex formation. The maintenance of an appropriate concentration of the impurity-removing material, for example from 0.001 to 10 wt .- $, based on the amount of Cu (I) halide present, can be ensured by the fact that one in the Koinpl exbil formation in the gas phase repeats a I ¹ eil or all of the particles of the -halogen as absorbents used Gu s (I)! ds withdrawing and if necessary by which the impurities-removing mixture coats again. On the other hand, the material removing the contaminants can also be brought into the complex formation zone, for example, by spraying (in the case of complex formation in the gas phase) or introducing the same into the dispersion containing the absorbent and diluent (in the case of complex formation in the liquid phase), see above that an adequate concentration of it is assured. The material is either directly applied to the particles of the Cu (I) halide used as an absorbent? or brought into close contact with the same so that the solid absorbent can absorb the contaminant ent removing agent. Therefore, the grease removing the contaminants can be incorporated into the feed stream and supplied with it, for example in cases where the feed is introduced into the complex formation zone in the gas phase in liquid or sprayable form.

According to a preferred embodiment of the present invention, in which the complex formation takes place in the gas phase, the particles of the respective Gu (I) halide serving as absorbent are used in a very porous form, ie a porosity of 10 $> (based on the total volume of a particle),

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at 550 to £ 10,000 pore diameter. Such porous Particles of Ou (I) halide are extremely absorptive and their use is made with Complex formation processes which are carried out in the gas phase are largely preferred.

These extremely porous particles of the copper halide serving as an absorbent can easily be made according to British Patent 1,074,233. The porosity becomes raw Copper (I) halides imparted by the fact that Bringing salts with a conditioning ligand under complex-forming conditions and then the complex is desorbed, whereby an activation of the particles of the Cu (l) halide is achieved because of them a high degree of porosity was given. The conditioning ligand used is able to with the respective Cu (l) halide to form a stable complex, the complex having a wol ratio of Copper to complex-forming (conditioning) ligands of more than 1: 1. The complex degradation is usually done thermally by heating the complex crude Salt carried out to split the complex, leaving the absorbent highly porous particles of Cu (I) halide can be obtained. In the procedures listed, either crude Ou- (I) halides are used in one dissolved in a suitable solvent or an aqueous or another dispersion of the same is formed, then the dissolved or dispersed particles added to complex formation with a conditioning ligand that is able to provide a stable Copper-ligand complex with a molar ratio of copper to complexing ligand of more than 1: 1 form.

If the copper (conditioning) ligand complex from a solution of the Cu (I) halide he was kept, the solution of the Gu (l) halide

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usually obtained by dissolving the crude Cu (I) halide at about -40 to 60 ° C monoolefin having 4-12 carbon atoms used in a solvent with stirring or other agitation to achieve adequate dissolution of the salt in the solvent to back up. The solutions obtained in this way are then filtered to remove insoluble parts prior to complex formation and degradation. Regardless of whether the absorption-active, highly porous Cu (I) halide particles were obtained by solution or dispersion processes or by some other suitable process, it is preferred to use those conditioning ligands which have a stable complex with an iole ratio of copper to be conditioned Form ligands of 2: 1 or more. Such compounds refer to both materials that only form complexes in the ratios of copper to complexing compounds of more than 1: 1 and to compounds that form complexes with a ratio of 1: 1 or less, which after complex breakdown form a permanent complex in a ratio of copper to complexing compound of more than 1: 1 and preferably 2: 1 or higher. Certain materials, such as ITitriles, diolefins, acetylenes, carbon monoxide, etc., which under normal conditions form a complex in the ratio of 2: 1, can be used to complex to achieve a ratio of copper to conditioning ligand of 1: 1 or less achieve. During the dissociation, the complex-forming material is selectively released from a layer of the Cu (I) halide until the permanent complex, namely the complex with a molar ratio of copper to conditioning ligand of over 1: 1, e.g. a stoichiometric complex with a Ratio of 2: 1, is completely formed before it is further broken down into the non-complex-bound (extremely porous) Cu (I) halide particles. In this regard, "complex" persistent ^{under M becomes a stoichiometric one}

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Understood complex that is persistent upon dissociation as described above. Such “conditioning ligands ¹¹ , which are used to produce the extremely porous halide absorption particles, are preferred if the complex formation is carried out according to the invention in the gas phase. However, the following compounds are not exclusively used as conditioning ligands: conjugated and unconjugated aliphatic, cyclic and alicyclic polyolefins with 3-10 carbon atoms, for example 1,3-butadiene, isoprene, piperylene, allene, octadiene, cyclohexadiene, cyclooctadiene, cyclododecyltriene; aliphatic and alicyclic unsaturated or saturated nitriles with 2-10 carbon atoms, propionitrile, acrylonitrile , Methacrylonitrile, ethacrylonitrile, etc., carbon monoxide, HCN us ^t / '. Of course, more than one of these functional groups can be present in a single molecule of a "conditioning ligand.

When carrying out the complex formation in the gas phase using the extremely porous, absorption-active Gu (I) halide particles obtained by the method described above, there is a substantial part, for example usually at least 25 wt .- ^, preferably about 50 up to 90 wt .- $ and more (90 +), based on the total amount of Cu (I) halide parts, made of extremely porous materials with a porosity of over about 10 % (based on

. ο

on the total volume of a particle) with a pore diameter of 550 to 10,000 Å, which was determined by measurements on the mercury porosimeter. The absorption capacity of these extremely porous particles is usually about 35 to 99 $> and more (99+) , preferably about 50 to 99 $ and more, based on the theoretical absorption capacity of the ligand to be obtained. If the ligand obtained is, for example, 1,3-butadiene, the theoretical absorption capacity depends on the stoichiometric ratio in which the 1,3-butadiene and the Cu -. (I) -

· * ■ original

Forms halide complexes. Forms 1 mole of 1,3-butadiene with 2 i> iol Cu (I) chloride complexes.

As mentioned above, the complex formation between the particles of Cu (I) halide and the complex-forming ligand in the feed stream is also carried out in the liquid phase become, which is even preferred. Any temperature and pressure conditions necessary to produce a solid insoluble Complexes of Cu (l) halosenide and a ligand to be obtained in the liquid phase are sufficient, can be used if the complex formation is to be carried out in the liquid phase. According to a preferred Implementation of the present invention is the complex formation in the liquid phase in a dispersion made, in which the particles of Gu (I) halide either in extremely porous form or in the form of raw salt particles in one essentially anhydrous liquid organic diluent are dispersed, the boiling point of which is higher than the Boiling point of the complex-forming ligand to be obtained. Then it is made from Cu (I) halide and ligand existing complex is desorbed in the presence of the liquid organic diluent to obtain the ligand. Usually, desorption is used to thermally separate the complexed ligand by heating the complex particles made in the presence of an organic liquid diluent. According to one of the particularly preferred embodiments of the present invention for complex formation in the liquid phase for the purpose Obtaining the ligand from the feed stream, this complex formation in the liquid dispersed phase numerous contact steps are made, which take place one after the other, with each complex formation at a lower one Temperature than the previous one takes place, and all stages being in the presence of the liquid organic Thinner work. With such a complex formation carried out at stage temperatures

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it is usually desirable to complex the formation so far as possible to carry out at the first (higher) temperature, as this increases the purity of the Ligand is improved.

The liquid dispersant used in performing the complex formation in the liquid phase Organic diluent is opposite to either Reaction with the Cu (I) halide inert, or, if it forms a complex with the same, it is subject less likely to form complex than the ligand to be recovered and does not contain excess water. For example, if the ligand to be recovered is ammonia, a dispersion of Cu (I) chloride particles

ψ can be used in acetonitrile, since ammonia is more easily absorbed by the Gu- (I) -chiοridteileheη than acetonitrile. The inert or less preferred absorbed liquid organic diluent can be any liquid, anhydrous, organic diluent whose boiling point is above the boiling point of the complexing ligand obtained from the feed stream, and which preferably does not under complexing conditions with the Cu (I) halide particles forms a stable complex. It is also preferred, but not absolutely required, that the liquid organic diluent have a boiling point above that

. each component of the feed stream lies. The specific liquid organic diluent or mixture of diluents used in a given case will of course depend on the ligand to be obtained and the components of the particular feed stream from which it is to be obtained. In view of this, the boiling point of the liquid organic diluent is usually above -12 ° C, the melting point below 21 C, at the process temperatures it has a low viscosity, usually dissolving less than about 5 %, preferably less than 1 %, of the Cu ( I) halide particles or the ligand complexes formed therewith. Furthermore, one can do it in the final

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The recovery process can be easily separated from the ligand obtained (as well as any other input components), preferably by simple distillation or evaporation processes, ura the desorbed ligand obtained as a product from the dispersion consisting of the liquid organic diluent and the Cu (l) halide particles " The following compounds, isomers, isomer mixtures and their mixtures thereof can be used as suitable liquid, dispersing organic diluents, although the list is not intended to represent a restriction: Paraffinic hydrocarbons with at least one carbon atom higher than the ligand to be obtained from the feedstock, e.g. Paraffins and Gy el oparaff ine with 3 -12 carbon atoms, in particular propane, n-butane, isobutane, n-pentane, isopentane, methyl cyclopentane, η-hexane, isohexane »cyclohexane, n-heptane, methylcyclohexane, isoheptane, n -Octane, isooctane, n-fonane, n-decane, n-undecane, n-dodeean, etc. the higher paraffins and cycloparaffins, as well as mixtures and isomers thereof, for example paraffins boiling in a narrow range, which correspond to the number of their carbon atoms to the CU- to C-, 2 "-3? ^ara ffi ^neil belong, individually or in mixtures (of these, the jenigeri with 5 or more carbon atoms, aB the paraffins with 5-12 carbon atoms are preferred); monocyclic aromatics with 5-12 carbon atoms including the alkylated monocyclic aromatic hydrocarbons with 1 to 6 carbon atoms in the alkyl groups, such as benzene, toluene, xylenes, ethyltoluenes, cymene, cumene, etc., other aromatics, such as those with more than 12 carbon atoms, such as bicyclic, tricyclic and tetracyclic compounds, including but not limited to the methylnaphthalenes and polymethylanthracenes and phenanthrenes and of course the less preferred absorbed organic materials with the physical properties listed above, e.g. acetonitrile, allyl chloride, allyl bromide, carbon tetrachloride,

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Ethyl chloride, ethyl bromide, dichloroethylene, dibromo ethylene, Propyl chloride, propyl bromide, butyl fluoride, Butyl chloride, butyl bromide, amyl fluoride, amyl chloride, AiHylbroiiiid etc. as well as compounds with various Halogen atoms in the molecule, such as difluorodichloromethane, ethane, etc. » The less preferably absorbed can also be used Monoolefins as liquid organic diluents el, such as higher-boiling, less preferably complex-forming monoolefins with more than 4 carbon atoms such as butene-1, isobutylene (where the ligand obtained is ethylene), pentene-1, hexene-1, heptene-1, 2,2,4-Irimethylpentene-1,2,2,4-Triinethylpentene-2, Octene-1, Non-1, decene-1, undecene-1, 5-methyldecene-1, dodecene-1 can be used both as isomers and in the form of mixtures containing two or more of these compounds.

If the complex formation is carried out in the liquid phase using Cu (I) halide particles in dispersed form, the dispersion can be easily carried out by adding the crude Gu (I) halide particles to the liquid organic diluent and stirring to ensure sufficient contact of the solid To secure salt particles with a feed containing the ligand, can be prepared. The expression solid Cu (I) -halide ¹¹ absorbent "refers here to the crude Cu (I) -halide salt. The feedstock can be brought into contact with the copper-containing dispersion containing the liquid organic diluent either in gaseous or liquid form» The dispersion is usually stirred during the complex formation in the liquid phase.The absorbing particles used, consisting of Cu (I) halide, should be essentially anhydrous and have a high purity, namely up to 95 % and more of pure commercial grade Cu (I) chloride, Cu (I) bromide or Cu (I) iodide, contain less than about 0.8 ° ß> moisture and be essentially anhydrous. Halide absorbent is Cu (I) chloride which is made up of 99 # and more

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pure Cu (I) salt, which is essentially free of moisture is, dvh. less than et ^ a 0.5 wt .- ^ Moisture (based on the dry Gu (I) chloride) contains.

In the working method with a dispersion, the dispersion usually contains 10-65 wt .- ^ enidteilchen absorbent Cu-Cl) _& halo, based on the total amount of solids and liquids contained in the dispersion. The size of the absorbent solid particles consisting of Cu- (I) -hjlo ^ enide can be between 0.05 and about 400 microns, with the usual average particle size between 0.1 and 250 lvikrons, preferably between 0.1 and 0.1 200 microns.

Will complex formation in the liquid phase carried out, for example by means of a dispersion, the contaminant removing gown can be added to the liquid organic diluent, for example by mixing this liquid agent with the liquid organic Diluent is added prior to adding the absorbent solids to form the dispersion. But it can also be added to the dispersion of absorbent solid particles and diluent, or before it is mixed with the liquid organic diluent on the particles of the Cu (I) chloride salt be applied. The contaminant removing agent can also be added to the feed will. When incorporating this material into the dispersion, no special procedure needs to be followed will. Any convenient suitable method will suffice, it being important that that which removes the contaminant Agent during complex formation is present in sufficient kengen to allow the removal of the strong mixed complex-forming, contaminating ligands, the have boiling points that are close together to favor.

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After the complex formation, it is made from Cu (I) -halogenide and the ligand existing complex is desorbed to give the ligand obtained as a product in high purity to release. Although the presence of the contaminant removing agent during desorption is not necessary, it is usually because of its strong affinity for the absorbing Cu (I) halide particles he wishes. It is essential here that, after the agent which removes the contamination, the complex formation takes place once of the contaminating ligand with the Cu (I) halide absorbent prevented during the complex formation of the ligand obtained as product from the feed stream has, it effectively removes the contaminating ligand from the after desorption of the Cu (l) ~ halide ligand complex has driven out ligands obtained. As stated above, it is generally desirable and It is expedient that the material which expels the contamination is also present during the desorption. this is of course the case when the complex formation occurs Process is carried out in which one works with dispersions in the liquid phase. In the latter case is the concentration of the impurity ent removing Mean during desorption about the same fourth as during complex formation.

As already stated above, the desorption can expediently be carried out by heating the complex-bound Particles are achieved to the ligand obtained in very high purity (compared to the concentration and purity in which it was present in the feed stream) to be thermally released from the same. Any Desorption conditions are used which do not thermally the ligand to be obtained destroy, or the absorbing Cu (I) halide small parts burn out so much that they for the further Use in the recovery of further ligands from the feed stream are unusable. The specific temperatures and pressures suitable for desorption

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depend on the specific complex to be disordered as well as other factors such as the specific liquid organic diluent used for the dispersion or the diluent mixture, etc.

After the complex formation and before the desorption, the complex-bound Cu (I) halide can participate be stripped to remove undesirable agents whose boiling point is below that of the diluent. Stripping to remove these less complex-forming, lower-boiling agents can be done by Contact of the complex-bound particles with a stripping hiedium be made. Therefore, when complex formations and desorption are carried out in the gas or liquid phase a stripping gas, e.g. a gas that which just contains ligands selectively obtained in high purity from the feed stream. if the ligand to be obtained that from a butadiene-containing one 1,3-butadiene derived from the feed stream can be 1,3-butadiene even be used as stripping gas.

Stripping the dispersion of Cu (I) halide and liquid organic diluents can be used in two ways be made thermally by heating the complex dispersion at temperatures that are at or preferably below 66 to 150 below the desorption temperatures which are to be applied in the subsequent complex-reducing stage. Possible liquid organic lost during stripping Diluent can be obtained by splitting off the diluent from the stripping gas under appropriate conditions Temperature and pressure conditions are recovered. Stripping can also be done by washing the stripping column be carried out in countercurrent with a suitable liquid or gaseous scraper, the one more preferably complex-forming ligand along with the Cu (I) halide particles as long as stripping at temperatures and pressures

BAD OBIGiNAL 109839/1624

is carried out, which does not cause any substantial degradation of the complex of the desired ligand complex. That Stripping can also be made by countercurrent washing with a liquid or stripping gas using of inert hydrocarbons, especially inert paraffins with 5-12 carbon atoms, nitrogen, nitrogen-containing mixtures, etc. are carried out. Various combinations of stripping agents can also be used be used. If the stripping is carried out in the dispersion, this is always in the presence of the liquid organic diluent done as a liquid.

For example, butenes and other less complexing compounds can be made from insoluble complex-bound Cu- (IJ-chloride-butadiene-particles stripped off by bringing the particles into contact with liquid n-pentane. Other stripping methods can also be used be applied. Are less complex-forming feed components from those in a liquid organic Diluents dispersed Cu (I) chloride butadiene particles stripped, butadiene gas can be blown through the dispersion to effect stripping.

Occasionally it may be necessary to

'' centering of the pollution-removing agent, that is present in the dispersion of the Gu (I) halide particles and the liquid organic diluent is to renew. This can easily be done by taking the appropriate amounts of this agent (to ensure the desired concentration during the complex formation) that of solid absorption particles and adding the existing dispersion to the diluent before or in the dispersion complex formation zone with stirring, a more uniform distribution of the impurities removing iuittels in relation to the absorbent Secure solid particles from Cu (l) halide. Additional (compensation) losses for the

10983 9/1624 BAD ORIGINAL

Cleanings of removing putty ice can be done periodically or continuously added to the dispersion of Ou- (I) halide and liquid organic diluent will.

Regardless of whether the complex formation and desorption took place in the gas or liquid phase the deaorbed Gu (I) halide particles can be used for further use in the selective recovery the ligand obtained as product from the charge in which it is contained are used, the only essential condition being that the contaminant removing agent present in the required concentration evenly distributed and in en & eni contact and association with the absorbing solid Cu (I) halide particles remains, since the contaminant removing agent is the removal of the undesired, strongly mixed complex-forming ligand with a boiling point close to it from the Compl ex training b ev-irct.

A large number of ligands can, according to the invention, from the feed streams in which they are themselves in proportion small concentrations such as 15 wt% fc or lower can be recovered. Appropriately These ligands can be divided into two categories, namely those that are persistent complexes with the absorbing Cu (I) halide in molar ratios of more than 1: 1, and those that form persistent complexes in col proportions of copper too complex-forming ligands obtained as a product of lsi forms. Suitable examples of the ligands with the Ratio of 1: 1 (those which form a complex in the molar ratio with the respective Cu (l) -halofc; enide absorbent of 1: 1), which can be obtained from feed streams, are not included in the following restrictive list reproduced: Monoolefine with 2-20 carbon atoms, wi-j e.g. ethylene, propylene,

BATH ORIGINAL 109833/1624

Butenes (butene-1, butene-2 and isobutylene), styrene, Vinyl toluene, vinyl cyclohexane, unsaturated aldehydes, unsaturated Alcohols, unsaturated esters, unsaturated acids, e.g. allyl alcohol, acrolein, acrylic acid, methacrylic acid, Alkyl acrylates and alkyl metal acrylates with 1-8 Carbon atoms in the alkyl groups (methyl acrylate, Ethyl methacrylate, ethyl methacrylate), amines, halogenated olefins, e.g. vinyl chloride, chlorobutenes, allyl halides, such as allyl chloride, etc.

If, however, after a long period of use, the absorption activity and the absorbency of the in dispersion

fc decreases so that the yield in the process decreases sharply, the absorption activity and the absorption capacity of the Cu- (I) halide solids can be regenerated in that they form a complex with a "conditioning ligand" capable of is a complex with the Cu (l) halo ₃ -enid in Fiolverhältnis from ^ 1. form 1 to ", namely a ligand having a stable complex with a kolverhältnis of copper to the complex-forming ligands of above 1: 1 The complex is then broken down. The complex formation and the subsequent complex breakdown can take place either in the gas phase or in the dispersion

Fe salt the required absorption activity and the required absorption capacity due to the formation of pores in salt after the complex degradation. This desorption is usually accomplished by heating the crude salts previously complexed. This thermal dissociation of the complex releases the absorption-active Cu (I) halide particles. After this treatment with the "conditioning ligand", the solid Cu (I) halide particles have an extremely porous structure, for example a porosity of over about 10 % (based on the total volume of a particle) of pores

ο a pore diameter of 550 to 10000 A, which means

10 9 8 3 2/1624 bad original

determined based on measurements with the mercury porosimeter became. Suitable useful "conditioning ligands" usually form as exemplified above listed conditioning ligands, stable complexes, the txol ratio of copper to conditioning Ligands is 2: 1 or more.

G-suitable examples of complexing ligands in a molar ratio of 2: 1, ie greater than 1: 1 (ligands which form a permanent complex in a molar ratio of copper to the complexing ligand obtained as the product of more than lsi), which are of increased purity obtained by the improved process according to the invention are given in the following, non-restrictive list. All ligands listed above which are suitable as "conditioning ligands" for the production "of extremely porous absorption-active Cu (I) halide particles from their corresponding crude salts; halogenated conjugated or non-conjugated aliphatic cyclic and alicyclic polyolefins, e.g. 2-ChIοr-1, 3-butadiene, chloro- and bromopiperylenes, chlorocyclohexadienes, unsaturated ethers, such as divinyl ethers, acetylenic halides, alcohols, acids and esters, such as, for example, propargyl chloride, propargyl brofiide, propargyl alcohol, propargyl acetate, propargylic acid, etc., various acid groups substituted with Kltr.il , Ethers, * esters, such as 2-hydroxypropionitrile substituted unsaturated nitriles etc.

The present invention is illustrated in more detail by the following examples in which all percentages and parts are by weight unless otherwise specified. In all examples, with Exception to example 5 »is the active absorbent

Material a porous CuCl (> 10 follows porosity and

ο a pore diameter of 550 to 10000 A), which according to the

procedure given above was prepared.

1098 39/1624

B is ρ ie 1

Liquid n-pentane dispersions containing 50 to 60 Cu (l) chloride contained, -were produced by that the Cu (l) chloride to the liquid n-pentane is added and the dispersion is stirred. When trying that contained a contaminant removing agent this agent before the addition of the Cu (I) chloride particles to the pentane dispersion diluent on the same upset. Then the butadiene-containing feed stream was into the Cu-ClJ-chloride-n-pentane dispersion and the complex formation in the liquid. Dispersion phase Performed at the complex formation temperatures listed below in experiments 1 to 22. The feed stream had the following composition, with the respective concentration of the train leading Vinyl acetylene is specified separately for each individual experiment:

Components of the linsatsaat erial s

Concentration (G-ew.-90

Propane propylene and isobutane methane n-butane Ethane and ethylene butene-1 and isobutylene t-butene-2-c-butene-2-butadiene-1,3 I-diethylacetyl-en-butadiene-1,2 Ethylacetylene Vinylac etylene

0.0354

0.7991

0.0000

1.3282

0.0000 47.0737 10.9564

7.1960 32.2261

0.0334

0.1782

0.0666 as shown in Table I.

109839/1624

Dispersion solids became the stream of complex formation with 1,3-butadiene within one hour stripped at the temperatures given below under normal pressure. Subsequently, the complex was inside 0.1 to 1.0 hour by heating to 66 to 74 ° C below Use of nitrogen to promote desorption (■ unless otherwise stated in Table I below) reduced. Substantially no complex degradation occurred during the stripping. The stripping became for removal of the complex-bound Cu (I) chloride particles from the dispersion carried out by following the above subjected to exhorted heating. Then the dry stripped particles were given the above Temperatures (with the exception of those listed in Table I) are reduced. In Table I results are summarized, obtained from 25 tests. In the main, the effect of the varying Vinylacetylene concentration in the feed, complex formation temperatures, presence and absence of specific, impurity-removing putties as well as the different concentrations of Contamination removal agents shown.

109839 / 1Ü24 BADORIGtNAL

Table I.

Try Mr.

Converted vinyl acetylene, parts / Hill.

9100

9IOO

9IOO

9IOO

9IOO

9IOO

9IOO

Q CO CD O3

Complex formation temperature, C stripping temperature, C

Pollution Removal Agents

Additional concentration

(% By weight, based on solid Cu (I) chloride

solid complex-bound Cu (I) chloride, %>

Desorption product, wt .- ^

4.4 4.4 4.4 32.2 32.2 32.2 32.2 32.2 54 54 54 54 54 54 54 54

none

56

DMF

56

Vinylacetylene, parts / mill. 2054 butadiene-1,3 99.5557 99.8127

DMF

4.5

54

none

51

28 347 99.9607 99.7833

DMF

45

DMF

0.3

50

DMF

O ¹

DMF

49

39 40 11 40 99.8897 99.8314 99.8596 99.8947

DMF - Ν, Η-dimethylformamide j "^ ⁺ NMP φ N-methylpyrrolidone; * ⁺⁺ WMF = ^: N-methylformamide; DMCA» Ν, Ν-dimethylcaproamide; NB = not determined; DMCCA = a mixture of N, N-dimethylcaprylamide and Ν, Ν-dimethylcaproamide from approximately equal amounts by weight.

CD

CO

CQ CD

Table I (continued)

() M Test 6, recycled, solid copper (l) -chloria without addition of the impurities-removing means (). ² Experiment 7 """"""

() ⁵ «Experiment 5""""""»

() ⁴ . Experiment 20 """ ^tf " »

( ) * ' = Dispersions in the liquid phase, stripped with 1,3-butadiene within 60 minutes at 27 C and

ο
in a complex formation reactor within 60 minutes at 93 C with nitrogen at normal

pressure released.

() = Dispersions in the liquid phase, with essentially pure 1,5-butadiene within 60 minutes.
Stripped at 54 ° C and in a complexing reactor within 60 min. At 93 C with
Nitrogen degraded at 1 atm. Pressure.

CO. £> · CO CD CD

Table I (continued)

Attempt no. 9 10 11 12th 13th 14th 15th 16 Vinylacetylene used,
Parts / mill. 5000 1400 1400 1400 1400 1400 1400 1400 Complex formation temperature, C 15.6 4.4 4.4 4.4 15.6 15.6 15.6 32.2 Stripping temperature, C 54.4 O ⁵ O ⁵ O ⁶ 54.4 54.4 54.4 54.4 Pollution removing DMF none DMF ME none DMF DMF ⁺⁺ NMP

O additional concentration
"*" (Weight Jo ₁ based on solid Cu (I) chloride

* "solid, complex-bound Cu (I) chloride, $>

Desorption Product, Wt .- $ Vinylacetylene, Parts / Mill. 28 butadiene-1,3 99.9735

3.0

N.B.

207 93.8275

3.0 N.B.

10 94.0654

3.0

N.B.

3 99.1684

63

1.3
61

2.7 0.5

1174 39 37 25th 99.7602 99.9737 99.9834 99.8522 1643964

Table I (continued)

Attempt. No.

Vinylacetylene used, parts / mill.

Complex expansion temperature, C Stripping temperature, C

»Pollution Removal

> Medium

^> Additional concentration

y (G-ew, - ^, based on solid Cu (I) chloride

j solid, complex-bound ^. Cu (l) chloride, #

17th 18th 19th 20th 1400 I25O 1100 1100 32.2 10.0 4.4 4.4 54.4 54.4 54.4 54.4 *** NMF DMF none DMF 0.3 1.6 - O ⁵ 46 67 59 55

Desorption product,

Vinylacetylene, parts / mill. 42 butadiene-1,3 99.9095 99.7122

21st

22nd

DMF

DMF

0.3 0.7

50 63

24

1100 1100 9100 9100 9100

32.2 40.5-1.67 15.6 32.2 15.6

54.4 54.4 54.4 54.4 54.4

DMCA DMCA DMCCA

o, 7 0.7 0.7 £ 3

61 50

29 14 14 48 28 99.6589 99.8784 99.8884 99.9447 99.8686 99.9159 99.8805

CD

4> -

CO

UD CO -O ·

Example 2 t

A cyclic complex formation of 1,3 butadiene was carried out in a one liter stirred autoclave. The complex formation medium was a 50 wt .- / oi _ö e dispersion of Cu (I) chloride (> 10? £ owned porosity) in heptane. The starting material for the dispersion were unsaturated compounds with 4 carbon atoms of the same composition as in Example 1, with the difference that it contained 3700 parts / million vinyl acetylene. In the first cycle there was no impurities removing agent, while in the second, third and fourth cycle about 1 wt .- ^ of a mixture of ΙΓ, Ν-dimethylcaprylainide and Ν, Ν-dimethylcaproamide (JJxlCCä), based on the CuCl-G content, was present.

The insert was added to the dispersion and the complex formation was carried out first at 32 °, then at 21 ° G. The dispersion was stripped within one hour at 54 ° C under a pressure of 1 kg / cm with pure 1,3-butadiene, and then the complex cm degraded within 20 minutes at about 88 ⁰ C and 1 kg /. The dispersion was cooled and the cycle repeated. A solids sample was taken within each cycle after stripping and before complex breakdown. This solid was subjected to complex degradation in the laboratory and the purity of the desorbed 1,3-butadiene product was evaluated by critical gas chromatography to achieve the result set out below. As shown in the third and fourth cycles, during the cycle the effect of the contaminant removing DMCCis used as an additive becomes stronger. maintains and improves looks bar, probably due to better dispersion on the solids.

33 - ■ *

Table II:

cycle

Vinyl acetylene in use,

Parts / Hillion 3700 3700 3700 3700

on the solids,

Weight # none (l) 1.0 1.0 1.0

Product purity

1,3-butadiene, wt. # 99.86 99.88 99.90 99.97

Vinylacetylene, parts / mill. 316 83 14 11

(1) DMCCA added before cycle 2, no further addition for cycles 3 and 4

Example 3:

This example shows the effect of the additional concentrations at different temperatures as well as ■ shows the contaminant concentrations in the insert.

In these series of tests, a discontinuous Complex formation method applied, then the complex degradation was carried out in the laboratory and the The purity of the product 1,3-butadiene which had been bound to the complex was investigated. In feathers Case was a 50% by weight CuGl di sp er si ο η ( > 10 # porosity) in heptane is used as a complex-forming medium. The complex formation was carried out at the desired temperature in the dispersion phase. That The feed material for the dispersion was unsaturated Compounds with 4 carbon atoms, corresponding to the

109839/1624

Material of the J3spl. 1, but with the difference that it contained different amounts of vinyl acetylene. the The results below show that only a small amount of the contaminant removing agent is required and that this amount decreases as the impurity concentration decreases or the temperature decreases increases.

109839/1624 bad original

Table III

Effect of the different concentrations of the additive.

Try Mr.

Vinyl acetylene in use, _, parts / million

i £ DMCCa ' ¹ ' concentration, ^ wt .- $ _f based on d. J ₂ solids content

I ^ complex formation temperature,

Product unit

9100

no

32.2

1,3-butadiene, wt .- ^ 99.78 Vinylacetylene, parts / läill. 347

9100

0.7

32.2

99.92 28

9IOO I4OOO I4OOO I4OOO I4OOO

none 1.4

no

15.6 32.2 32.2 32.2 15.6

14000 I4OOO I4OOO

3.3

15.6 15.6 15.6

99.91 99.72 99.84 99.84 99.57 99.89 99.91 99.94 66 637 206 47 l, 6ll 257 120

(l) Ν, Ν-dimethylcaprylamide and Μ, Ν-dimethylcaproamide

CD

GO

CO CO

Example 4:

As in Example 2, ethylene was obtained by cyclical complex formation and complex breakdown in the dispersion phase. In this Pail, a crude ethylene stream with the following composition was introduced into a 50 wt .- ^ r-ige CuGl dispersion (^> 10% porosity) at -16 ⁰ G and 6.3 atmospheres in heptane. The corresponding product composition of the ethylene complex obtained after the degradation of the dispersion complex at 27 ° C and 1 kg / cm is given below. A second experiment using the same feedstock, in which 1 % 1 \ f, N-dimethylcaproamide (DMGA) was added to the pesticides, is also listed below. These data demonstrate the effect of the added contaminant removing agent in reducing the product concentration of undesirable components in the separation of a 1: 1 complex from CuCl.

Table IV:

cycle ■ - "- · 109839 / mission
material 1 2 Ü> 1CA concentration,
W-ew .-%, based on
the solids content 10.88 no 1.0 Product composition, mol% 0.30 H ₂ 38.31 0.00 0.00 co ₂ 39.99 0.00 0.00 CH ₄ 10.14 0.45 0.12 O ₂ H ₄ 0.05 98.49 99.65 ° 2 ^H 6 0.33 0.98 0.23 Connections with 3 and more
Carbon atoms 16 2 4 0.00 0.00 acetylene 0.08 0.00 BATH ORIGINAL

Example 5 _t i

The procedure of Example 4 is repeated using crude, dry, commercially available Cu (I) chloride as the absorbent and a dispersion liquid of 75% by weight of heptane and 25% by weight of hexene-1. The absorbent consisting of CuGl forms a complex with ethylene with a capacity of up to 60 % of the theoretically possible value for a CuCl-ethylene complex with a ratio of 2: 1. A similar test without 1-hexene only leads to 25 to 33-fold complex formation, based on the theoretical value.

In a third cycle in which hexene-1 was present, ϊί, Ν-dimethylcaproamide became one concentration of 1.0% by weight, based on the solids content. added. This leads to an improvement in the purity of ethylene, which is essentially the same as in Example 4 is.

Example 6:

In accordance with the procedure of Example 5, a complex is formed for the selective recovery of propylene in the dispersion phase. This dispersion consists of a 50% by weight dispersion of CuCl (^> 10-6 porosity) in decane. The feed to the dispersion is a crude stream containing propylene and other 3 carbon compounds as shown in the table below. The cycles are carried out under the same conditions as in Example 5, both without the use of a contaminant-removing additive3 and with 2 Grew .- # (based on the solids content) of F-methylpyrrolidone, which is added to the dispersion. These results demonstrate the effect of the additive in improving purity with another 1: 1 complex of GuGl.

t09839 / 1624

Table V:

attempt

N-K e t hyl ρ yrr oil i do n concentration, Wt .- $, related to o.d. Solids content

no

Product combination ;,

Ethyl acetylene allene
propane
Propylene

Exnsatz- 0.10 0.01 material 0.15 0.01 0.12 1.32 0.22 0.25 98.43 99.78 37.62 62.01

example

In a cyclical test plant working with a fluidized bed, the co: plex formation was carried out with ethylene in the gas phase. In this procedure, fluidizable particles (held by-average particle size 40 LC of CuCl (> 10 porosity) in a vertical fluidized bed. They were current to the one used in Example 5 using atm at 21 and vortexed -32 ⁰ C to produce a ethylene-complex They were then stripped with pure ethylene at -18 ° C. and 21 ° C. and finally the complex was broken down with nitrogen at 21 ° C. and 43 ° C. Both experiments were carried out without addition and using 0.5% by weight. - # of a mixture of N, N-dimethylcaprylamide and ST, N-dimethyl capro amide (DL4CGA) carried out in a ratio of 50. The results given below show the effect of the additive on complex formation in the gas phase In addition , the solids become much better in those containing the additive

BATH ORIGINAL

- 59 -

Cycle moves, which is a further advantage for the additive used in the fluidized bed of the gas phase «

Table VI:

attempt

BriCCA conc.; Ntration, wt. -Fo, bez. Ru;,. Solid content

no

0.5

Product composition, LoI-J

GH ₄ G ₂ H ₄ ^C 2 ^H 6

Compounds with 5 and 3h carbon atoms

acetylene

mission
material 0.00 0.00 10.68 0.02 0.00 0.50 0.61 0.05 33.51 98.15 99.86 59.99 1.05 0.09 10.14 0.00 0.00 0.05 0.21 0.00 0.55

example

8th :

To obtain acrylonitrile, the complex was formed in the dispersion phase in a one-liter stirred autoclave. ., A synthetic mixture of 70 wt .- ^ acrylonitrile and 30 wt -fo acetonitrile at -18 ⁰ C and 1 50 wt .- $ a -. CuCl strength dispersion in toluene was added. The dispersion was then concentrated. The solids were washed three times with fresh toluene. The dispersion was then heated, the acrylonitrile was dissolved out of the complex and evaporated at the boiling point of toluene. The cycles were both with and without the contaminant removing additive

109839/4624

BATH ORIGINAL

5 G-ew .- ^ b WjE-Dimethyloleylamide, based on the content carried out on solid GuCl. The purity given below was obtained for the acrylonitrile product.

Table VII:

attempt

Ν, ΐί-dimethyloleylafnid,

based on solid CuCl none

Product purity, Crew.-9 lbs

Acrylonitrile 87.2 98.1

Acetonitrile 12.8 1.9

Example 9:

Corresponding to the procedure of Example 2, isoprene was obtained by complex formation in the dispersion. The 50% by weight dispersion of CuCl in iso octane was at 16 C and 1 at. with a crude containing isoprene and other compounds with 5 carbon atoms Treated stream of the composition given below. The dispersion was then at 43 ° C and 1 at. stripped with pure gaseous isoprene, heated to 93 C and then the complex is broken down. the Cycles were performed without the contaminant removing additive and with 0.1 wt. based on the CuCl content. The following Results show the effect of the additive in ensuring improved isoprene purity.

109839/1624

BATH ORIGINAL

Table VIII:

attempt mission 1 2 UMF, wt .-? £, or solid material CuGl 42.61 no 0.1 Product composition, wt .- $ 0.37 Isoprene 13.36 98.67 99.84 1,4-P entadiene 1.21 0.21 0.02 Pentene-1
C-pentene-2 0.32 0.75
0 03 8; i3 TP ent- 2 0.11 0.01 Pentane 0.02 0.00 Ethyl acetylene 0.21 0.00

Example

10:

According to the procedure of Example 9, styrene was phase by complex formation in the dispersion won. The dispersion consisted of 50 wt .-; # OuGl in pentane. In this dispersion was at 4 G and 1 at. a feed stream of 60 wt% styrene and 40 wt% ethylbenzene was introduced. The dispersion was then used twice washed with pentane in countercurrent, then the solids and dry solids were up 93 0 heated. The styrene was accumulated as it was developed. On one cycle, that became the impurity Removal agents not added and in a second there were 2 wt .- # N, N-dimethylformamide during complex formation (DMJ?) Available. Complex formation took place on the second cycle using the listed Additive takes place five times faster, creating another unexpected benefit for the presence of the Additivesa became apparent. The purity of the following specified Styrofoam products affects the effect

id2L

of the present invention in improving the purity of the styrene.

Table IX; Cycle 1 2

109839/1624

.-SS, related
ad solids content none

Product purity,

Styrene 82 95

Ethylbenzene 18 5

Claims (25)

Claims; 1. Process for the selective production of complex-forming ligands which are formed with copper (I) chloride, Copper (l) bromide or copper (I) iodide as an absorbent preferably form stable complexes, a charge containing the ligand forming the ligand-absorbent complex brought into contact with the absorbent and the complex is broken down to obtain the ligand in greater purity, thereby characterized that "one the complex formation in the presence one? Putty ice removes impurities, the end (A) compounds of the formula in which R "is an alkyl group with 1-12 carbon atoms and η is an integer from 2 to 12, or (B) compounds of the formula: BAD OBtGlNAL 109839/1624 OR '
/ R-C-N in which R and R ¹ denote hydrogen or alkyl groups having 1-18 carbon atoms and R "denotes an alkyl group having 1-18 carbon atoms, or (C) Mixtures of the compounds (A) and (B). 2. The method according to claim 1, characterized in that (1) one containing the ligand Charging with complex formation of the ligand to be obtained in the liquid phase with an essentially anhydrous dispersion of solid copper (I) chloride particles as an absorbent in a liquid organic diluent with a boiling point above that of the preferred Complex forming ligand, which consists of compounds that are less preferred with copper (l) chloride Form complexes as the ligand to be recovered contacts and (2) the complex in the presence of the liquid organic Degrades diluent with recovery of the ligand, which preferably forms complexes, in pure form, the complex formation taking place in the dispersion and that likewise taking place in the dispersion Complex degradation can be carried out in the presence of the impurity-removing putty ice. 3. The method according to claim 1, characterized in that that one (1) a 1,5-butadiene together with im same range of boiling, difficult to separate butenes and vinyl acetylene containing feed with a essentially anhydrous dispersion of solid copper (l) chloride particles with an average particle size of 0.1-250 '/ - in hydrocarbons with 5-12 carbon atoms and a boiling point above that of 1,3-butadiene 109839/1624. bad ORIGINAL for selective complex formation of 1,3-butadiene with Bringing copper (l) chlarrid in the liquid phase to sufficient temperatures and pressures and (2) the Copper (I) chloride-1,3-butadiene complex with gextfinnung of essentially pure 1,3-butadiene, which is essential less vinylacetylene than the feed contains, in (rainy the diluent breaks down, with complex formation and complex degradation in the dispersion in the present from 0.01 to 3% by weight of the contaminant removal Medium, based on the amount of copper (l) chloride present. 4. The method according to claim 1, characterized in that the complex formation in the gas phase and absorbent particles with a porosity greater than about 10% (based on the total volume of a particle) on pores with a diameter ο used from 550 to 10000 ä. 5. Process according to Claims 1 to 4, characterized in that the impurities are removed Agent in a concentration of 0.001 to 10 wt. #, Preferably 0.01 to 3 size v: .- $, based on the iylenge of the absorbent used. 6. The method according to claim 1 to 5 »characterized in that the compound (B) is an N, N-Di-O ₁ -bis C, -alkylamide of an alkanecarboxylic acid having 1 to 18 carbon atoms, preferably Ν, ϊΤ-dimethylformamide, H , K-dimethylcaproamide or a mixture of N, N-dimethylcaprylamide and N, N-dimethylcaproamide is used. 7. The method according to claim 1 to 5 »characterized in that that as compound (A) an N-C ^ - to C. Alkylpyrrolidone, preferably N-methylpyrrolidone, is used. BATH 109839/1624 8. The method according to claim 1 to 2, characterized in that a ligand is used which with the copper used as an absorbent (l) chloride, copper (l) bromide or copper (I) iodide resistant complex in a wood ratio of copper too complex to form a ligand greater than 1: 1 able. 9. The method according to claim 8, characterized in that the ligand is an organic nitrile, acrylonitrile is preferably used. 10. The method according to claim 8, characterized in that the ligand is a multiolefin, preferably a diolefin, in particular 1,3-butadiene, isoprene or allene is used. ₌ 11. The method according to claim 1 or 2, characterized in that a ligand is used which with the copper (l) chloride, copper (I) broaiid or copper (I), iodide used as the absorbent, a stable complex in a wood ratio from copper to ligand of 1: 1 is able to form. 12. The method according to claim 11, characterized in that that the ligand is an i'ionoolefin, preferably a monoolefin with 2 to 20 carbon atoms, in particular ethylene, propylene or butene used. 13. The method according to claim 1, characterized in that there is used as the absorbent copper (I) chloride used. 14. The method according to claim 7, characterized in that there is used a liquid organic diluent Ver, the paraffin with 5 and more 109839/1624 Contains carbon atoms. 15. The method according to claim 2 »characterized in that that one uses a liquid organic diluent which is a monocyclic aromatic Contains hydrocarbons with 6-12 carbon atoms and Ms to six alkyl substituents. 16. The method according to claim 2, characterized in that a liquid organic diluent is used used, which is a laonoolefin with 4 and more carbon atoms and containing at least two carbon atoms more than the selectively recoverable honoolefin. 17. The method according to claim 3 »characterized in that that as an inert hydrocarbon as a diluent a paraffin with 5-7 carbon atoms or a monocyclic aromatic hydrocarbon having 6 to 12 carbon atoms and up to six alkyl substituents used. 18. The method according to claim 3, characterized in that after the complex formation, but before the desorption in the presence of the hydrocarbon serving as the inert diluent and the agent removing impurities, the butenes are stripped from the dispersion. 19. The method according to claim 18, characterized in, that at least partially 1,3-butadiene is used as stripping gas for stripping. 20th middle! to obtain a ligand with improved Purity according to the method of claims 1 to 19, characterized in that it is used as a solid absorbent Copper (I) chloride, copper (I) bromide or copper (I) iodide and 0.001 to 10.0 wt. # of an impurity contains removing agent that consists of. .Γ 109839/162 4 (A) compounds of the formula CH (CH ₂ ) _n in the R "is an alkyl group with 1-12 carbon atoms and η is an integer of 2 Ms 12, or (B) compounds of the formula 0 R ¹ -N R " R-G-N in which R and R ^{1 are} hydrogen or an alkyl group having 1-18 carbon atoms and R ^{11 is} an alkyl group having 1-18 carbon atoms, or (G) a mixture of compounds (A) and (B). 21. Agent according to claim 20, characterized in that the agent removing the impurities is present in a concentration of 0.01 to 3 _f 0 wt .- ^, based on the absorbent. 22. Hittel according to claim 20 and 21, characterized in that that it contains copper (l) chloride as an absorbent. 23. Composition according to claim 20 to 22, characterized in that it is also a liquid dispersant 109839/162 4 BATH ORIGINAL 1643364 contains organic diluent. 24. Means according to claim 23, characterized in that that it is 10 to 65 percent by weight absorbent, based based on the total weight of absorbent solids and liquid diluent. 25. Means according to claim 20, characterized in that it consists essentially of a dispersion of iestem copper (I) chloride as an absorbent with a content of 0.01 to 3.0 wt .- # of an F ₅ N-Di-G ₁ - to C.-alkylamids of an alkanecarboxylic acid with 1 to 18 carbon atoms, preferably a mixture of If, N-dimethyl caprylamide and N, N-dimethylcaproamide, based on the absorbent solids. Pur Esso Research and Engineering Company 103839/1624